Global climate models from Germany (green), Canada (red) and USA (black) scaled to the Kenai predict that post-2030 mean summer temperatures will always be above the threshold for spruce bark beetle outbreaks. Observed temperatures are from the Homer airport since 1932. Lower bar graph shows annual beetle-kill for southern Kenai since aerial surveys began in 1971 (US Forest Service). Ed Berg graphic.
The article (URI below) appeared in the Kenai National Wildlife Refuge’s Refuge Notebook series.